I am currently using a Fluxing agent made by GC electronics part # 10-200 Solder Flux
_____ From: kicad-users@yahoogroups.com [mailto:kicad-us...@yahoogroups.com] On Behalf Of Bernd Wiebus Sent: Monday, March 01, 2010 12:49 AM To: kicad-users@yahoogroups.com Subject: Re: [kicad-users] rework/unsoldering Hello Juliorz > I am experiencing problems with a board that I design using KICAD. > It is almost impossible to remove all solder from a hole. I am wondering > if > I have enough clearance between > the component lead and hole. I knew this problem, too. I see it very common at rework. And, indeed, it mostly comes from a to small gap between the component lead and the hole. But it is common for all layout programs, not only kicad. The reason is. that therev has to be made a decision between easy rework and save keeping the component in place during transport, if the component is assembled, but not yet soldered. In most cases, the decision ist made for production, not for rework. If you made the decision designing for rework, you should create your own modules, by taking the original modules and change the hole diameters. Sometimes you will also get a conflict between hole diameter, annular around the hole, an isolation gab to the next pin. > Even after I use heat to remove the > component, > getting all the solder out of the > empty hole is very difficult using traditional > industry techniques. This could also happen if you use leadfree solder. If you have no safety problem in using leaded solder, swamp the gap with leaded solder, because this decreases the melting point. But be aware, that there could be a safety/reliability problem mixing different solder types, especial mixing stibium alloyed solder and lead alloyed solder. Next what you could do, is using fluxing agent. Take colophony (wood resin) and dissolve it with isopropanole. This will make a good fluxing agent. At very bad cases, use stearine as fluxing agent. Use simple a pure stearine candle. But be aware, most candles are not made from stearine but from paraffine. Paraffine will omly create a charred mess at your board. > for the holes or if this is an issue to do > with the manufacturing company that is making the boards for me?? > This could also be a reason. You have the board, you can measure this. Look also at the component leads, too. Perhaps they are exeptionel thick? With best regards: Bernd Wiebus -- GMX DSL: Internet, Telefon und Entertainment für nur 19,99 EUR/mtl.! http://portal. <http://portal.gmx.net/de/go/dsl02> gmx.net/de/go/dsl02
